If At First You Don't Succeed, Ai, Ai AgainBy Rabbi Jack Abramowitz
The problem caused by Achan resolved, Hashem sent Joshua back to Ai. Joshua took 30,000 soldiers by night to the rear of the city. They pretended to flee as they had the first time. When the King of Ai had his forces pursue the Jewish army, he left the city unprotected. Joshua had hidden 5,000 troops, who then easily took the city. When the army of Ai (who were pursuing Israel) saw their city burning, they became confused and were easily overpowered when Joshua’s army stopped pretending to flee. The King of Ai was captured and executed.
After this victory, Joshua built an altar on Mt. Eival and wrote the Torah on the stones taken from the Jordan back in chapter 4. The Tribes stood on Mt. Eival and Mt. Gerizim in order to recite the blessings and curses, as was called for in Deut. 27.